The present invention relates to a pair of drive heads for a storage media drive. More particularly, the present invention relates to a pair of opposing drive heads for being positioned in a storage media drive to read a flexible storage media positioned within such drive.
In a typical storage media drive, a storage media is passed by a drive head such that the drive head can read information from and/or write information to the storage media. Particularly where the storage media is a two-sided disk or other similar object, the information may be stored on both sides thereof. Accordingly, the typical drive includes a pair of opposing drive heads, and the storage media travels between such opposing drive heads. Of course, in the situation where a drive includes multiple media such as multiple disks (usually stacked on a single spindle), each disk travels between its own pair of drive heads.
When the storage media is a disk, to facilitate the reading and/or writing operations of the storage media drive, the storage media is rotated at an angular speed high enough to cause each drive head to xe2x80x98ride upxe2x80x99 onto an air bearing formed between the face of the drive head and the surface of the rotating storage media. As should be understood, the air bearing is a formed cushion of air that facilitates smoother operation of the storage media drive, and also prevents unnecessary wear on the storage media that would otherwise be caused by the contact of the drive heads on the rotating storage media. Of course, some contact is normal, especially in connection with a flexible storage media.
In one typical embodiment of the opposing drive heads, each drive head has a pair of longitudinally extending generally parallel raised rails, where the surface of each raised rail includes a longitudinally extending air bearing surface. As should be understood, the air bearing surface on each rail is the substantially flat portion thereof that directly faces the storage media, and that most contributes to the maintenance of the created air bearing. A drive sensor is positioned on a first one of the air bearing surfaces of each drive head, and the drive heads are positioned to oppose each other such that the drive sensor on each drive head is opposed by the second one of the air bearing surfaces of the other drive head (i.e., the air bearing surface that does not have the drive sensor). By being so opposed, the storage media will travel adjacent each drive sensor in close proximity to such drive sensors.
However, if the storage media is relatively flexible, as can be the case, and should the drive heads become mis-aligned such that one of the drive sensors becomes unopposed, the flexible storage media will not travel adjacent each drive sensor in close proximity to such drive sensors. In particular, and as should be understood, a rotating, generally flexible storage media rotating past an un-opposed air bearing surface tends to curve away therefrom. If such un-opposed air bearing surface should include a drive sensor, it is likely the case that the curved-away storage media is too far from such drive sensor to allow such drive sensor to read to or write from such drive media.
To complicate matters, in a typical drive head, the drive sensor is positioned toward the trailing termination of the air bearing surface on which it resides, and in some instances can even be positioned at such trailing termination. As may be understood, the amount of mis-alignment that can be tolerated decreases as the drive sensor gets closer to the trailing termination. At the trailing termination, then, practically any mis-alignment will result in one of the drive sensors being unopposed by an air bearing surface.
Accordingly, a need exists for a pair of opposing drive heads in a storage media drive wherein mis-alignment of the drive heads can be better tolerated, even if the drive sensors are positioned at the trailing terminations of respective air bearing surfaces.
The present invention satisfies the aforementioned needs by providing a pair of opposing drive heads for being positioned in a storage media drive to read and/or write a storage media that is interposed between the drive heads for travel therebetween. Each drive head has a sensor face that includes first and second generally parallel longitudinally extending air-bearing surfaces. Each air-bearing surface has a leading termination and a generally longitudinally opposing trailing termination. The storage media travels adjacent the sensor face of the drive head in a traveling direction extending generally along the air-bearing surfaces from the leading terminations to the trailing terminations.
A drive sensor is positioned on the first air-bearing surface of the sensor face a distance D1 from the trailing termination of such first air-bearing surface. The trailing termination of the second air-bearing surface of each drive head extends farther a distance D2 in the traveling direction than the trailing termination of the first air-bearing surface of each drive head. The drive heads are opposingly positioned with respect to each other such that the first air-bearing surface of each drive head is generally opposed by the second air-bearing surface of the opposite drive head, such that the leading terminations of the drive heads generally oppose each other, and such that the trailing terminations of the drive heads generally oppose each other.
The drive sensor of each drive head is overlaid by the second air-bearing surface of the opposite drive head when the drive heads are aligned with respect to the traveling direction. The drive sensor of each drive head remains overlaid by the second air-bearing surface of the opposite drive head when the drive heads are mis-aligned with respect to the traveling direction by as much as the sum of D1 and D2.